What is the predominant manner in which most metals and non-metals unite chemically?

The predominant manner in which most metals and non-metals unite chemically involves electron transfer. This process occurs during the formation of ionic bonds, where metals, which tend to lose electrons, transfer them to non-metals, which are more likely to gain electrons.

In this interaction, metals typically have few electrons in their outer shell, and by losing them, they can achieve a stable electron configuration, often resembling the nearest noble gas. Non-metals, on the other hand, have more electrons in their outer shell and require additional electrons to fill their valence shells to achieve stability. This transfer of electrons leads to the formation of positively charged metal cations and negatively charged non-metal anions, which then attract each other due to their opposite charges, thus forming an ionic bond.

While covalent bonds also represent a way elements can unite, especially among non-metals, the specific interaction between metals and non-metals is characterized by this electron transfer phenomenon. The focus on gaining or losing electrons in the context of metal and non-metal bonding delineates the basic principle of ionic bonding, solidifying electron transfer as the underlying process in their chemical union.